1. Field of the Invention
The present invention relates to refrigeration systems and in particular a dual purpose, valve which is adapted to open a Schroeder-type core valve and a standard or service valve fitting with minimal loss of refrigerant.
2. Description of the Prior Art
This invention is an improvement over U.S. Pat. No. 4,332,273 dated June 1, 1982, and the prior art cited therein.
Due to the concern for the pollution of the atmosphere caused by vapor refrigerants, such as, Freon, various types of connectors have been designed to prevent the escape of vapor from a refrigerant system which is being resupplied or repressured from a pressurized refrigerant source. The refrigerant systems are usually provided with either a Schroeder-type valve, which is well known in the prior art and/or a standard or service valve fitting. Prior to the above-referenced patent, as the connector is tightened on one or the other of the valves, refrigerant from the pressurized source would leak either as a liquid from the high pressure side of the refrigerant system or vapor from the low pressure side, before a seal is formed by the connector. Occassionally when this occurs liquid refrigerant being released into the atmosphere from a high pressure causes moisture to freeze on the connector, nut and threads making its difficult to complete the connection and/or remove same. As a result, pressurized refrigerant sprays into the atmosphere and many times, on the hands of the operator, which can cause severe burn. If the nut freezes and cannot be turned the refrigerant from the whole system may be lost.
A standard or service type valve is usually permanently a part of the refrigerant system. The valve includes a standard threaded connector for coupling with a pressure supply of refrigerant. To repressure the system, a valve associated with the refrigerant is opened, thence the service valve is opened to provide communication with the system.